package ecommerce.interceptor;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class AuthenticationInterceptor implements Filter {

	private String onErrorUrl;
	
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request; 
	    HttpServletResponse res = (HttpServletResponse) response;
	    HttpSession session = req.getSession(); 
	    
	    Object user_id = session.getAttribute("current_user");
	   
	    if (user_id == null) {
	    	res.sendRedirect(onErrorUrl);
	    } else {
	    	session.setAttribute("loginError", false);
	    	chain.doFilter(request, response);
	    }
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
	    onErrorUrl = filterConfig.getInitParameter("onError");    
	}
}